No joke, it really will. All you have to do is walk into a retailer this Saturday, whip out your smartphone and use Amazon's Price Check app to collect price data on in-store items. In exchange, the company will offer you a discount of five percent (or up to $5) on "select items" in electronics, toys, music, and other product divisions, though you'll only be able to use it a maximum of three times. The campaign represents Amazon's latest attempt to creep int
